Braided hemostasis shaft for improved torsional response

ABSTRACT

A medical insertion device includes an elongated shaft extending from a proximal end to a distal end and having flexibility sufficient for insertion through a working channel of an endoscope along a tortuous path. The elongated shaft includes a coil extending from the proximal end to the distal end and having a channel extending longitudinally therethrough and a braided portion extending around a portion of the coil, the braided portion including a plurality of lines wound together such that first and second ones of the lines intersect to enclose a predetermined angle therebetween, the angle being between 25 and 55 degrees.

PRIORITY CLAIM

The present application claims priority to U.S. Prov. Appln. Ser. No.61/867,935 filed Aug. 20, 2013. The entire specification of the aboveapplication is incorporated herein by reference.

BACKGROUND

Pathologies of the gastro-intestinal (“GI”) system, the biliary tree,the vascular system and other body lumens are commonly treated throughendoscopic procedures, many of which require active and/or prophylactichemostasis to control internal bleeding. Tools for deploying hemostaticclips via endoscopes are often used to control internal bleeding byclamping together the edges of wounds or incisions. These tools areinserted into the body through a working channel of an endoscope.Specifically, the tools may be attached to an elongated coil insertedthrough the endoscope to provide the flexibility necessary to permitinsertion through a tortuous path in the body. However, elongated coilsoften do not provide torsional stiffness sufficient to translate adesired rotation imparted to the proximal end of the coil (e.g., at aproximal handle) to the hemostasis device (e.g., clip, etc.) coupled tothe distal end of the coil. Specifically, as coils compress or expandwhen subjected to a twisting load until an outside diameter of thespring meets an opposing force, much of the energy input into the coilis dissipated before being transmitted to the distal end of the coil.Thus, a significant portion of rotation applied to a proximal end of acoil causes expansion/compression of the coil and does not translate ina corresponding rotation at the distal end thereof.

SUMMARY OF THE INVENTION

The present invention relates to a medical insertion device comprisingan elongated shaft extending from a proximal end to a distal end andhaving flexibility sufficient for insertion through a working channel ofan endoscope along a tortuous path. The elongated shaft includes a coilextending from the proximal end to the distal end and having a channelextending longitudinally therethrough and a braided portion extendingaround a portion of the coil, the braided portion including a pluralityof lines wound together such that first and second ones of the linesintersect to enclose a predetermined angle therebetween, the angle beingbetween 25 and 55 degrees.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a shaft according to a firstexemplary embodiment of the present invention;

FIG. 2 shows a perspective view of a shaft according to a firstalternate embodiment of the invention;

FIG. 3 shows a perspective view of a shaft according to a secondalternate embodiment of the invention;

FIG. 4 shows a perspective view of a shaft according to a thirdalternate embodiment of the invention;

FIG. 5 shows a perspective view of a shaft according to a fourthalternate embodiment of the invention;

FIG. 6 shows a perspective view of a shaft according to a fifthalternate embodiment of the invention;

FIG. 7 shows a perspective view of a shaft according to a sixthalternate embodiment of the invention;

FIG. 8 shows a perspective view of a clipping device fitted with theexemplary shaft of FIG. 1 ; and

FIG. 9 shows a partial cross-sectional view of the clipping device ofFIG. 8 .

DETAILED DESCRIPTION

The present invention may be further understood with reference to thefollowing description and the appended drawings, wherein like elementsare referred to with the same reference numerals. The present inventionrelates to a flexible shaft for permitting the transmission of rotationapplied to a proximal end of the shaft to a corresponding rotation ofthe distal end of the shaft so that this rotation may effect a devicecoupled to the distal end of the shaft when that device has beeninserted into the body along a tortuous path to, for example, performhemostasis. It is noted, however, that the exemplary shaft according tothe invention may be used with devices used to perform any endoscopicprocedure including, but not limited to band ligation, injectiontherapy, thermal electrohemostasis, combination therapy needle,biopsies, fine-needle aspiration and procedures for the treatment of theupper and lower gastrointestinal (“GI”) tract. The exemplary shaftaccording to the invention comprises an elongated coil pre-wound with apredetermined diameter, length, number of turns, etc., as will bedescribed in greater detail later on. The shaft further comprises abraided element wound over the coil, the braided element formed as apredetermined plurality of wires wound together in a predeterminedpattern relative to one another, as will also be described in greaterdetail later on. A braid angle of wires comprising the braid is selectedto enclose an angle including or within 25-55 degrees. As will bedescribed in greater detail later on, this range provides the shaft withthe required torsional stability to transmit rotation to the devicecoupled to the distal end of the shaft while still permitting the shaftto flex to permit insertion thereof through the tortuous anatomy. Itshould be noted that the terms “proximal” and “distal,” as used herein,are intended to refer to a direct toward (proximal) and away from(distal) a user of the device.

As shown in FIG. 1 , a device 100 according to an exemplary embodimentof the invention includes an elongated body 101 extending longitudinallyfrom a proximal end (not shown) accessible to a physician or other userin an operative configuration to a distal end (not shown) which, in use,is inserted into a living body to a site adjacent to target tissue. Thedevice comprises a first portion 102 formed as a coil, the coilcomprising an elongated wire or filament 104 wound to a coiledconfiguration and having a predetermined spring constant, as thoseskilled in the art will understand. The first portion 102 is sized topermit insertion thereof into a working channel (not shown) of anendoscope (i.e., with an outer diameter of the device 100 being lessthan an inner diameter of the working channel). A lumen 106 extendsthrough the device 100 along a longitudinal axis 108 thereof. In anexemplary embodiment, the first portion 102 is formed of a single wireor filament 104 wound into the configuration of FIG. 1 . It is notedhowever, that any number and arrangement of wires 104 may be employedherein without deviating from the scope of the invention. For example,the first portion 102 may comprise multiple coils provided over oneanother, with each of the coils being wound in an opposing directionrelative to an adjacent one of the coils.

A second portion 110 of the device 100 is formed as a braided outerportion enveloping the first portion 102. The second portion 110comprises a plurality of lines or wires 112 wound together in a braidedarrangement over the coiled first portion 102. The exemplary embodimentof FIG. 1 depicts eight lines or carriers 112. It is noted, however,that any number of lines may be employed without deviating from thescope of the invention. In an exemplary embodiment, each of the lines112 comprises four individual strands 114 such that a total of 32strands form the second portion 110. It is noted, however, that eachline 112 may include any number of filaments without deviating from thescope of the invention, wherein the number of filaments 114 used maydepend on an outer diameter of each filament 114. For example, each line112 may comprise any of one, two, three, four, five or more individualstrands 114, as will be described in greater detail in laterembodiments.

Furthermore, each of the lines 112 may include a different number ofindividual strands 114 to affect an overall stiffness of the secondportion 110 and, consequently, the device 100, as those skilled in theart will understand and as will also be described in greater detail inlater embodiments. In another embodiment, the braided second portion 110may be unbalanced to simulate dual coils formed with opposing windings,as those skilled in the art will understand. For example, the braidedsecond portion 110 may comprise a first line 112 formed with one or morestrands 114 having first diameter wound with a second line 112 formedone or more strands 114 having a second diameter different from thefirst diameter. In an exemplary embodiment, the diameter of a pluralityof individual strands 114 forming a line 112 is substantially the same.The strands 114 according to this exemplary embodiment have asubstantially circular cross-section although any other cross-sectionalshape may be used without deviating from the scope of the invention,including, but not limited to rectangular and oval.

The lines 112 are braided with a predetermined braid angle relative toone another. As shown in FIG. 1 , the lines 112 intersect one another atcrossing 116. Portions of the lines 112 extending away from each of thecrossings are angled to enclose an angle α therebetween. In a firstexemplary embodiment, the angle α is 40.5°. In another exemplaryembodiment, the angle α is 37.5°. In yet another exemplary embodiment,the angle α may be any angle including and between 25°-55°. Theexemplary braid angle α is selected to provide a proper balance ofbending and torsional stiffness for the device 100 to perform in atortuous path. Specifically, the present invention establishes that abraid angle of approximately 55° or greater increases the bendingstiffness to a level above that suited for bending through a tortuouspath. The present invention further establishes that a braid angle ofless than 25° does not provide enough torsional stiffness to transmitrotation along the coil when it is bent along a tortuous path. Theexemplary range according to the invention provides a balance oftorsional stiffness and rotational transmittal to permit insertion ofthe device 100 through a tortuous path while transmitting rotationimparted to a proximal end of the coil along the coil to a distal endthereof. However, in applications where low tortuosity is to beencountered, a braid angle=55° may be used. Similarly, in applicationswhere high tortuosity is encountered, a braid angle=25° may be used.

It is noted that, although the embodiment of FIG. 1 is depicted with auniform braid angle α throughout its length, the braid angle α may bemodified in different portions of the device 100 without deviating fromthe scope of the invention. Although, braid angles of less than 25° andgreater than 55° are unsuitable for use along the majority of the lengthof these coils, small portions of the coils that require either extraflexibility or increased stiffness may be formed with braid anglesoutside the range. For example, a first section of the length of thesecond portion 110 adjacent to a distal tip of the device 100 may beformed with a braid angle α less than 25° for increased flexibility, thefirst section having a high pick count. The length of the first sectionis dependent on the specific application (e.g., tortuosity of targetanatomy). As the tortuosity of the anatomy increases, the deflectabilityof the first section decreases to achieve a desired torsional/rotationalperformance. In another embodiment, instead of providing a first sectionwith a braid angle α of less than 25°, the braid may be omitted in thisregion to further increase flexibility of the first portion 102. In oneexemplary embodiment, the first section may extend up to 15.24 cm fromthe distal end of the first portion 102. Similarly, a second section ofthe second portion 110 may be formed with a braid angle α greater than55° when additional stiffness is required. Similar to the first section,a length of the second section is dependent on a tortuosity of thetarget anatomy as well as other factors including, but not limited to, alength of the first portion 102 which will remain outside of theendoscope during the procedure, desired stroke length during insertioninto the working channel of the endoscope, etc. For example, the lengthof the second section may be larger when used with an uppergastrointestinal (GI) endoscope since the distance between the proximalhandle of the endoscope and the entry port of the endoscope issubstantially large when compared to procedures for other portions ofthe anatomy. In another embodiment, the second section may be positionednear the proximal end of the second portion so that it remains outsideof any tortuous anatomy in an operative configuration.

The torsional stability and bending stiffness of the second braidedportion 110 may also be modified by changing a pick count thereof. Thepick count refers to the number of braid crossings formed over a unitlength of the coil. In an exemplary embodiment, as shown in FIG. 1 , thepick count may comprise 17 crossings per a unit length of 10 mm. It isnoted, however, that any other pick count may be used without deviatingfrom the scope of the invention. As those skilled in the art willunderstand, the pick count varies according to the number of individualfilaments 114 forming the braided second portion 110, the number oflines 112 and the type of braid pattern selected.

The exemplary braided second portion 110 in the exemplary embodiment isformed of a biocompatible material such as stainless steel, or otherbiocompatible metals and alloys, biocompatible polymers, plastic coatedwire or a hybrid of materials. In one embodiment, each of the individualstrands 114 is formed with a plastic coating which may be reflowed(e.g., by heating) to lock the braided second portion 110 in a desiredconfiguration. Proximal and distal ends of the braided second portion110 may be tapered to lie flush against the first portion 102. Thistaper may be formed in the lines 112 or may be machined after braided(e.g., by grinding, etc.).

The device 100 may be formed such that the first portion 102 includes areduced diameter portion 105 at a distal end thereof. As those skilledin the art will understand, this configuration provides addedflexibility in the distal end of the device to, for example, aid intraversal of the device 100 through a tortuous path in the body. Thereduced diameter portion 105 may be provided at one or more of a distalend of the body 101, proximal end of the body or at any positiontherebetween. In an exemplary embodiment, the reduced diameter portion105 is ground down to have a diameter smaller than that of outlyingsections of the first portion 102. It is noted that, due to the addedflexibility imparted by the reduced diameter portion 105, this portionmay not include the second portion 110 extending thereover. In such anembodiment, the second portion may terminate at a location proximal tothe reduced diameter portion 105. Lines 112 comprising the secondportion 110 may gradually taper down in diameter at the termination toprevent damage to the working channel of the endoscope. In anotherembodiment, the first portion 102 has a diameter uniform along itslength, with the second portion 110 terminating proximally of a distalend of the first portion 102 to increase flexibility at the distal end.In yet another embodiment, the first portion 102 may be fitted with aplurality of second portions 110 over a length thereof, the plurality ofsecond portions 110 being separated from one another to define regionsof increased flexibility along the length of the device 100.

As shown in FIG. 8 , the exemplary device 100 may be used in a clippingapparatus 800. The clipping apparatus 800 includes a cylindrical capsule810 releasably coupled to a distal end of a the elongated body 101 ofthe device 100. As described in greater detail earlier, an outerdiameter of the second portion 110 of the device 100 may gradually tapertoward the distal end of the elongated body 101. The capsule 810receives the proximal end of a single hemostatic clip 812. The clip 812,which is coupled via a control wire 814 to a proximal actuating handle816 remaining outside the body, includes a pair of tissue gripping arms818 for bringing together separated portions of tissue (e.g., to close awound). As with closure devices generally, the clip 812 is designed tobe left in place after a procedure has been completed to hold togetherthe edges of tissue while natural healing processes knit them together.When this process has progressed sufficiently that the tissue can holditself together without assistance from the clip 812, the clip 812 maybe removed (e.g., through a separate procedure) or may be left in placeto be sloughed off naturally as the gripped tissue is shed.

In an operative configuration, the elongated body 101 is inserted into aliving body (e.g., after being passed through a natural body orificealong a tortuous path) so that a distal end thereof is positionedadjacent a target location. At this desired position, the clip 812 ismoved distally out of the capsule 810 so that the arms 818 spread apartinto the tissue-receiving configuration under their natural bias. At anytime prior to or after advancing the clip 812 out of the capsule 810,rotation may be applied to a proximal end of the elongated body 101 torotate the capsule 810 and clip 812 to orient the arms 818 as desiredrelative to the target tissue. The control wire 814 is then actuated todraw the clip 812 proximally into the capsule 810 closing the clip arms818 over the target tissue. When drawn into the capsule 810 to thismaximum proximal extent, the capsule 810 constrains the arms 818 toremain in a closed position with the distal ends of the arms 818 drawntogether. At this point, additional proximal force applied to thecontrol wire 814 increases tension on the control wire until apredetermined tension is reached at which a joint between two parts, 820a, 820 b of a core member 822 coupled between the control wire 814 andthe clip 812 fails. This releases the capsule 810 and the clip 812 fromthe elongated body 101 and locks the clip 812 in the closed positionover the clipped tissue.

The capsule 810 in this exemplary embodiment is removably connected tothe elongated body 101 by a bushing 822. As the severed proximal portion820 a of the core member 820 is drawn proximally out of the capsule 810,it pushes a bushing support 824 out of engagement with tabs 826connecting the bushing 822 to the capsule 810 thereby detaching thecapsule 810 from the elongated body 101. That is, when the bushingsupport 824 is moved out of a position in which it supported the tabs826 in a radially outward position, the tabs 826 spring radially inwardout of engagement with corresponding windows in the proximal end of thecapsule 810. This separates the capsule 810 from the bushing 822attached to the elongated body 101, allowing the apparatus 800 to bewithdrawn from the body while leaving the clip 812 in place over thetarget tissue.

As shown in FIG. 2 , a device 200 according to an alternate embodimentof the invention is substantially similar to the device 100 and likeelements have been referenced with like reference numerals, except asnoted below. The device 100′ comprises a plastic extrusion 220 formedover the braided second portion 110. The plastic extrusion 220 ispositioned over the braided second portion 110 and reflowed (e.g., byheating) to lock the braided second portion 110 in a desiredconfiguration over the first portion 102. In another embodiment, theplastic extrusion 220 may be positioned between the first and secondportions 102, 110 and subsequently reflowed (e.g., via heating) to movethe device 200 to a locked configuration in which the first and secondportions 102, 110 are not movable relative to one another. By providingthe plastic extrusion 220 over an outer surface of the braided secondportion 110, a protective coating is provided to shield the workingchannel (not shown) of the endoscope (not shown) from damage while alsopreventing/minimizing kinking of the device 200 as it is insertedthrough the working channel, as those skilled in the art willunderstand. The exemplary plastic extrusion 220 may be formed as a heatshrink tube.

FIG. 3 depicts a device 300 according to another embodiment of theinvention, wherein the device 300 may be moved to a locked configurationwithout the use of a plastic extrusion. The device 300 is substantiallysimilar to the device 100 and like elements have been referenced withlike reference numerals, except as noted below. Specifically, the braidpattern design of a braided second portion 310 may be formed to lockover the first portion 102 by using a locking pattern of braid along asingle section, multiple sections or the entire length of the device100. That is, crossings 116 of lines 312 of the device 300 interlockwith the peaks and valleys formed by the wound wire 104 forming thecoiled first portion 102. The braid crossings may be formed such thatsome crossings 330 occur in valleys 340 of the coiled first portion 102and other crossings 332 occur in peaks 342 of the coiled first portion102. The crossings may be formed to occur in one of the peaks, valleysor a combination of the two, as shown in FIG. 3 to lock the secondportion 310 to the coiled first portion 102. This configuration may beused to simulate a rip-stop style fabric such that the second portion310 is resistant to unwinding or other damage. If a section of thesecond portion 310 is damaged, the exemplary construction will preventthe damage from spreading to other parts of the second portion.Furthermore, the exemplary construction disclosed above assists indistributing stress loads on the individual crossings 330, 332 tofurther prevent the application of a strain that may lead to a breakagethereof.

In an exemplary embodiment, the device 300 is formed with four lines orcarriers 310, each including four strands 112. It is noted, however,that any variation in the number of lines 310 and strands 112 per linemay be used without deviating from the scope of the invention.

In yet another embodiment, the second portion 110, 210, 310 may belocked in position via a mechanical treatment including, but not limitedto, crimping, welding and swaging the second portion 110, 210, 310 tothe first portion 102.

FIG. 4 depicts a device 400 according to another embodiment of theinvention. The device 400 is formed substantially similar to the device100, except as noted below. The device 400 comprises a braided secondportion 410 formed of groups of lines 412 each comprising two filaments414. A pick count of the second portion 410 over a length L1 may begreater than the pick count of the device 100 to provide increasedstiffness to the device 400. The pick count may be selected to conformto the requirements of a particular procedure and may vary along alength of the device 400. As shown with respect to the device 500 ofFIG. 5 , the pick count may be decreased over the length L1, resultingin a corresponding increase of the angle α.

The second portion 410 is formed with a braid pattern selected so that afirst negative space 440 (i.e., the substantially diamond shape opening)formed between a first set of adjacent lines 412 has a different sizethan a second negative space 442 formed between a second set of adjacentlines 412. This pattern is imparted to the second portion 410 during abraiding process. This pattern allows for longitudinal expansion andcompression of the device 400 during use, thus aiding in insertion ofthe device 400 into the body. In the present embodiment, the firstnegative space 440 is originally larger than the second negative space442. It is further noted that the braid may be formed to having anynumber of negative spaces 440, 442 having different dimensions to imparta desired flexibility to the device 400. Furthermore, the braid may bepatterned so that only a predetermined length thereof includes thedifferent dimensions of the negative spaces. For example, in onenon-limiting example, only a distal tip of the device 400 may includethe negative spaces having different dimensions. The exemplary featuresof the device 400 may further be used in combination with any of theother features disclosed herein to impart a desired flexibility toselect portions of the device. It is noted that the braid patternsdisclosed above is exemplary only and variations thereof are envisionedwithin the scope of the invention.

As shown in FIG. 6 , a shaft 600 according to yet another embodiment ofthe invention is substantially similar to the shaft 100 except as notedbelow. The shaft 600 includes a plurality of single wires or strips 612braided together. Each of the single wires 612 is formed with a flat,substantially rectangular cross-section. It is noted however, that anyother cross-sectional shape may be used without deviating from the scopeof the invention including, but not limited to circular and oval.

FIG. 7 depicts a device 700 according to another embodiment of theinvention. The device 700 is formed substantially similar to the devicesdiscussed earlier, except as noted below. A second portion 710 of thedevice 700 comprises a first line 712 a having strands 714 a of a firstdiameter, the first and second lines 712 a, 712 b being braided to forman unbalanced braid pattern. The second portion 710 also comprises asecond line 712 b having strands 714 b of a second diameter smaller thanthe first diameter. That is, each of the four strands 714 a of the firstline 712 a all have the same first diameter while each of the fourstrands 714 b of the second line 712 b all have the same seconddiameter. The consequence of this structure is that, while braiding thefirst and second lines 712 a, 712 b a tension on each of the lines isaltered to increase and decrease tension in respective portions of thesecond portion 710. Specifically, as those skilled in the art willunderstand, a tension on the larger diameter first line 712 a will begreater than a tension of the second line 712 b. In another embodiment,the unbalanced braid may be achieved by braiding the first line 712 a ina clockwise direction while braiding the second line 712 b in acounter-clockwise direction. This type of unbalanced braid may be formedof first and second lines 712 a, 712 b having the same diameter ordifferent diameters. It is noted that although the device 700 has beendescribed with first and second lines 712 a, 712 b, any number of linesmay be used in the device 700 without deviating from the scope of theinvention.

The exemplary embodiments of the invention permit the application of anexternal rotation to the devices 100-700, wherein the entire device100-700 may be rotated to impart a corresponding rotation to a mechanism(e.g., a clipping device) attached to a distal end thereof. A surgeon orother user may impart this rotation with or without the use of a handleprovided on a proximal end of the device. In contrast, a control wiremechanism, as used in current devices requires the use of a handle inorder to impart rotation to a mechanism coupled thereto. The exemplaryexternal rotation of the devices 100-700 according to the inventionprovide the further advantage of transmitting rotation without bowing orwinding up. Specifically, control wire based rotation mechanisms aresubject to winding up during rotation and causing a whipping anduncontrolled movement of the distal end thereof. The exemplary devicesare formed to prevent such a winding or bowing and are capable oftransmitting rotation effectively and precisely.

The exemplary braided second portion according to the invention may beformed over the coiled first portion during manufacture and may beformed via a knit or crochet pattern.

It will be understood by those of skill in the art that individualfeatures of the embodiments described above may be omitted and orcombined to form alternate embodiments. Furthermore, it will beunderstood by those skilled in the art that various modifications can bemade in the structure and the methodology of the present invention,without departing from the spirit or scope of the invention. Forexample, although the present invention has been described with respectto a clipping device, the exemplary system and method may also be usedto perform biopsy procedures or any other medical procedure whereinimproved rotation of a component is required in combination with afunction of opening/closing a device, extending/retracting a device intotissue, etc., as those skilled in the art will understand. It istherefore respectfully submitted that the exemplary shaft according tothe invention may be employed with and within any other medical devicerequiring precise rotational control without deviating from the spiritand scope of the invention. Thus, it is intended that the presentinvention cover the modifications and variations of this inventionprovided that they come within the scope of the appended claims andtheir equivalents.

1-20. (canceled)
 21. A medical insertion device, comprising: a handleincluding an actuator; and an elongated shaft extending between aproximal end rotatably coupled to the handle to a distal end, theelongated shaft having flexibility sufficient for insertion through aworking channel of an endoscope along a tortuous path, the elongatedshaft including and being coupled to the actuator so that actuation ofthe actuator rotates the elongated shaft about a longitudinal axisthereof, the elongated shaft including a tubular member and a braidedportion extending around a distal portion of the tubular member, thebraided portion including a plurality of lines wound together such thatfirst and second ones of the lines intersect at crossings to enclose apredetermined angle therebetween, the angle being at least 25 degreesand less than 50 degrees, wherein each of the first and second ones ofthe lines includes at least one filament, a diameter of the filaments ofthe first one of the lines being different from a diameter of thefilaments of the second one of the lines.
 22. The medical insertiondevice of claim 21, wherein the tubular member is formed as a coilextending from the proximal end of the elongated shaft to the distal endof the elongated shaft and having a channel extending longitudinallytherethrough.
 23. The medical insertion device of claim 21, furthercomprising a device coupled to a distal end of the elongated shaft fortreating tissue within a living body, the device being coupled to theelongated shaft so that, upon actuation of the actuator, rotation of theelongated shaft is transmitted to the device to rotate the device abouta longitudinal axis thereof.
 24. The medical insertion device of claim21, wherein the first one of the lines includes one of one, two, threeand four filaments and the second one of the lines includes one of one,two, three and four filaments.
 25. The medical insertion device of claim24, wherein each of the lines contains the same number of filaments. 26.The medical insertion device of claim 21, wherein the braided portionincludes eight lines wound together.
 27. The medical insertion device ofclaim 22, further comprising a plastic extrusion on the braided portionto lock an orientation of the braided portion relative to the coil. 28.The medical insertion device of claim 21, wherein the lines are woundwith a predetermined pick count.
 29. The medical insertion device ofclaim 21, wherein each of the lines has a circular cross-section. 30.The medical insertion device of claim 21, wherein a distal end of theelongated shaft is formed to engage a tissue-clipping device.
 31. Themedical insertion device of claim 23, wherein the device is one of aband ligator, a hemostatic clip, a biopsy needle, a fine needleaspiration device and a combination therapy needle.
 32. The medicalinsertion device of claim 21, wherein the angle at which the first andsecond ones of the lines intersect varies along a length of theelongated shaft.
 33. The medical insertion device of claim 21, whereinan outer diameter of a distal portion of the elongated shaft is reducedrelative to the outer diameter of a portion of the elongated shaftproximal thereto.
 34. The medical insertion device of claim 21, whereinan outer diameter of the elongated shaft gradually tapers to a distalend thereof.
 35. The medical insertion device of claim 22, wherein thelines are wound in a locking braid pattern such that crossings of thelines occur at one of valleys of the coil, peaks of the coil and acombination of the valleys and peaks of the coil.